The availability and use of “Cloud” computing has expanded exponentially in the past few years. Under a conventional computing approach, users run software applications on their own computers and/or access software services hosted by local servers (such as servers run by a business enterprise). In contrast, under cloud computing the compute and storage resources are “in the cloud,” meaning they are physically hosted at a remote facility that is accessed via a computer network, such as the Internet. Compute and storage resources hosted by a cloud operator may be accessed via “services,” where are commonly referred to as cloud-based services, Web services or simply services.
Cloud-based services are typically hosted by a datacenter that includes the physical arrangement of servers that make up a cloud or a particular portion of a cloud. Data centers commonly employ a physical hierarchy of compute, network and storage shared resources to support scale out of workload requirements. FIG. 1 shows a portion of an exemplary physical hierarchy in a data center 100 including a number L of pods 102, a number M of racks 104, each of which includes slots for a number N of trays 106. Each tray 106, in turn, may include multiple sleds 108. For convenience of explanation, each of pods 102, racks 104, and trays 106 is labeled with a corresponding identifier, such as Pod 1, Rack 2, Tray 1B, etc. Trays may also be referred to as drawers, and sleds may also have various forms, such as modules. In addition to tray and sled configurations, racks may be provisioned using chassis in which various forms of servers are installed, such as blade server chassis and server blades.
Depicted at the top of each rack 104 is a respective top of rack (ToR) switch 110, which is also labeled by ToR Switch number. Generally, ToR switches 110 are representative of both ToR switches and any other switching facilities that support switching between racks 104. It is conventional practice to refer to these switches as ToR switches whether or not they are physically located at the top of a rack (although they generally are).
Each Pod 102 further includes a pod switch 112 to which the pod's ToR switches 110 are coupled. In turn, pod switches 112 are coupled to a data center (DC) switch 114. The data center switches may sit at the top of the data center switch hierarchy, or there may be one or more additional levels that are not shown. For ease of explanation, the hierarchies described herein are physical hierarchies that use physical LANs. In practice, it is common to deploy virtual LANs using underlying physical LAN switching facilities.
Recently, Intel® Corporation introduced new rack architecture called Rack Scale Architecture (RSA). Rack Scale Architecture is a logical architecture that disaggregates compute, storage, and network resources and introduces the ability to pool these resources for more efficient utilization of assets. In contrast to the conventional rack architecture shown in FIG. 1, resources from multiple racks may be dynamically composed to form compute nodes based on workload-specific demands. In addition, to achieve high performance, communication between components in different racks is facilitated through use of Peripheral Component Interconnect Express (PCIe) cabling between the racks, which are connected by hand, with different rack configurations requiring different PCIe cabling configurations. If the PCIe cabling is miswired, resources in an RSA rack may be unavailable.